From owner-freebsd-hackers  Fri Jan  4  5:16:28 2002
Delivered-To: freebsd-hackers@freebsd.org
Received: from straylight.ringlet.net (discworld.nanolink.com [217.75.135.248])
	by hub.freebsd.org (Postfix) with SMTP id 5D4E637B405
	for <freebsd-hackers@freebsd.org>; Fri,  4 Jan 2002 05:16:21 -0800 (PST)
Received: (qmail 1043 invoked by uid 1000); 4 Jan 2002 12:48:22 -0000
Date: Fri, 4 Jan 2002 14:48:22 +0200
From: Peter Pentchev <roam@ringlet.net>
To: Martin Kaeske <Martin.Kaeske@II.Stud.TU-Ilmenau.DE>
Cc: freebsd-hackers@freebsd.org
Subject: Re: path_mtu_discovery
Message-ID: <20020104144821.A328@straylight.oblivion.bg>
Mail-Followup-To: Martin Kaeske <Martin.Kaeske@II.Stud.TU-Ilmenau.DE>,
	freebsd-hackers@freebsd.org
References: <20020104110806.A2138@walnut.hh59.local>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.2.5i
In-Reply-To: <20020104110806.A2138@walnut.hh59.local>; from Martin.Kaeske@II.Stud.TU-Ilmenau.DE on Fri, Jan 04, 2002 at 11:08:06AM +0100
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-hackers.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-hackers>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-hackers>
X-Loop: FreeBSD.ORG

On Fri, Jan 04, 2002 at 11:08:06AM +0100, Martin Kaeske wrote:
> Hello,
> I'm using FreeBSD-4.4-STABLE and have an OpenBSD-2.9 router to
> connect to the internet (via DSL). If i try to do a cvsup
> (cvsup.de.freebsd.org, cvsup2.de.freebsd.org, cvsup.freebsd.org)
> i'm getting a lot of "icmp: Destination unreachable, need to frag
> <mtu 1488>" messages and cvsup fails (timeout). The curious thing
> is if i disable net.inet.tcp.path_mtu_discovery or if i lower the
> MTU to 1488, everything is fine (of course). 
> That's why i wanted to ask wether FreeBSD fails to lower the MTU
> (it should lower it due to the icmp messages, shouldn't it?) or
> is there any pppoe specific problem between me and the cvsup servers?
> 
> Martin
> PS: AFAICS cvsup is the only problem ftp/http/nntp works fine

You have not, by any chance, firewalled ICMP replies, have you -
either outgoing on the router, or incoming on the FreeBSD box?

G'luck,
Peter

-- 
This sentence no verb.

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message